The present invention is in the field of antennas, and particularly relates to an antenna for use at, typically, 800 MHz in cellular telephone systems, and that is disguised as an AM-FM antenna of the type commonly used on automobiles and other vehicles.
Alternatively, the present invention can be viewed as a combination of high and low frequency antennas made in such a way that the combined antenna externally resembles a common type of antenna used at the lower frequencies.
The introduction of cellular telephone systems for use in vehicles was accompanied by numerous incidents of theft in which telephone instruments and related electronic equipment were stolen from the vehicles. Clearly, the peculiar corkscrew-shaped antenna used for the cellular telephone was being used by the thieves to determine which vehicles to attack. In some cities, the theft problem is still so severe that insurance coverage against theft damage to the vehicle is difficult to obtain.
The present invention solves this problem by providing an antenna that is effective for use with a vehiclemounted cellular telephone, but which resembles the AM-FM broadcast band antenna commonly used on vehicles. When the antenna of the present invention is installed on a vehicle, a thief cannot tell by looking at the antenna whether the vehicle is carrying cellular telephone equipment.
Another application of the present invention is in the law-enforcement field. Vehicles used in this field frequently are equipped with cellular telephone equipment. However, the use of the corkscrew antenna attracts attention to the vehicle and tends to identify it as a law-enforcement vehicle. For some types of law-enforcement work this is a considerable disadvantage.
Thus, there is a well-documented need for an antenna suitable for use with cellular telephone equipment, but which looks like the more conventional type of vehicle antenna.